Models for determining permanent strains in the subgrade and the pavement functional condition.

Two test pavements and one strengthened, overlaid variant of the second test pavement have been tested with the Danish Road Testing Machine. These test pavements were instrumented to enable measurements of strains and stresses in the pavement layers, and resilient and permanent strains in the subgrade at specific load repetitions. Using the measured response data from two test pavements, several models were developed to predict permanent strain in the subgrade and the surface rutting (and roughness) as a function of number of applied load repetitions, resilient strains and stresses. (a)